Novel compositions comprising carotenoids

ABSTRACT

A novel composition for delivering carotenoids (e.g. α- and β-carotene, lycopene) and/or other physiologically active ingredients to the colon of humans after ingestion and for producing liquid food compositions insusceptible to polyphenol-protein reactions can be obtained by encapsulating said active ingredients with pectin, in particular with low-methoxylated pectin.

The present invention relates to novel compositions comprisingcarotenoids and/or other physiologically active ingredients, inparticular in encapsulated form, to food items comprising suchcomposition, and to a process for their preparation.

Carotenoids have been reported to have beneficial effects on health. Forexample carotenoids such as β-carotene are thought to have an effectagainst colon carcinomas. It is believed that in order to have maximumbeneficial effect, the carotenoids should be in such a (physical) formthat they pass the stomach and small intestine without degradation orabsorption, as it is believed to be desired for the effect on the colonthat the carotenoids are available in the colon.

DE 19962427 discloses encapsulated bioactive components. The bioactivecomponents that are mentioned are microorganisms with probioticactivity. The covering agent consists of non-digestible fibrousmaterial. Examples given are: insoluble polysaccharides such as pectin,lignin, vegetable gums, but also soluble polysaccharides such as complexcarbohydrates (e.g. fructo- or galactooligosaccharides, beta-glucans,etcetera). Example 6 mentions the use of a combination of pectin andinulin for encapsulating Lactobacillus acidophilus.

U.S. Pat. No. 5,356,636 describes the preparation of vitamin orcarotenoid products in powder form by preparing an aqueous dispersion ofthe vitamins and carotenoids concerned and film-forming colloids andreducing sugars, converting this dispersion into powder from, andthermally treating the powder. The gelatin is used in combination withorganic amino compounds. The content of carotenoids is generally 5-50%.

U.S. Pat. No. 4,389,419 discloses a process for encapsulating oils andoil-soluble substances (e.g. vitamin A) in microcapsules. Themicrocapsules are a shape-retaining alginate matrix filled with aprecipitated polysaccharide and enclosing oil droplets.

EP 326026 discloses a method for reducing the oxidation of vitamins bycombining the vitamins with triglycerides, complexing agents andcovering agents, and optionally antioxidants. The covering agentsdisclosed are proteins, sugars, polysaccharides such as gum arabicum orstarch.

EP 986963 describes a method for the production of a light- andoxidation-stable lycopene in the form of a dry powder. Said stability isachieved by having at least 20% of the lycopene in a crystalline form.

U.S. Pat. No. 5,780,056 discloses microcapsules comprising a carotenoidand an edible oil. The coating material is based on gelatin. Themicrocapsules prevent the carotenoid from oxidation.

WO 91/06292 discloses a method for the production of water-dispersiblemicroparticles containing e.g. carotenoids. The microparticles areprepared by a specific process involving milling in water with ahydrocolloid. The hydrocolloid is reported to be gelatin, gum arabicum,protein or starch.

DE 19637517 reports a method for preparing a particulate cold-waterdispersible carotenoid preparation. This is achieved by making adispersion of carotene, optionally oil and/or emulsifier, in an organicsolvent, which dispersion is mixed with an aqueous solution of a colloidsuch as gelatin, starch, dextrin, vegetable protein, pectin, gumarabicum, casein.

Although the methods as reported may be suitable for some purposes, itwas desirable to have an alternative and improved preparation comprisingcarotenoids, which preparation should be such that the carotenoids arereleased in the colon, and not or to a limited extent only in theintestinal tract preceding the colon. Although β-carotene may be thepreferred active ingredient, the invention is also applicable to othercarotenoids and to other physiologically active compounds, respectively.

In accordance with the present invention It has been found that theabove objectives may be achieved by an edible composition comprising atleast 25% by weight, preferably at least 50% by weight, most preferablyabout 75% by weight of a pectin, particularly a pectin which gelatinizesby ionotropic gel formation, and at least 0.2% by weight of a carotenoidand/or another physiologically active ingredient, said percentages beingbased on the dry weight of the total composition.

Thus, in one aspect, the present invention relates to an ediblecomposition comprising at least 25% by weight (based on the dry weightof the total composition) of a pectin, particularly a pectin whichgelatinizes by ionotropic gel formation, and at least 0.2% by weight(based on the dry weight of the total composition) of a carotenoidand/or another active ingredient.

The pectin which gelatinizes by ionotropic gel formation is typically apectin having a degree of esterification below 50% which is alsoreferred to as low methoxylated pectin. Preferred pectins for use in thepresent invention are those having a degree of esterification betweenabout 30 and about 45% and comprise about 70 to 90% of galacturonic acidunits. The low methoxylated pectin may be an apple pectin or a citruspectin whereas beet pectins are unsuitable for inotropic gel formation.

Such compositions can suitably be in the form of a particulate matter,preferably a dry particulate matter.

In a further aspect, the present invention relates to a process for thepreparation of a composition comprising a carotenoid or mixture ofcarotenoids, and/or other active ingredients, which process includes thefollowing steps:

-   -   a) prepare an aqueous suspension comprising a pectin,        particularly a pectin which gelatinizes by ionotropic gel        formation,    -   b) add a composition comprising at least 0.5% by weight (based        on the dry weight of the final composition) of a carotenoid or        mixture of carotenoids, and/or other active ingredient(s) and,        optionally, an oil to the suspension as prepared in step a),    -   c) emulsify the mixture,    -   d) spray the emulsion as prepared in step c) into a bath of an        aqueous solution of a calcium salt,    -   e) separate the formed microparticles from the bath and,        optionally, wash the microparticles, and    -   f) optionally dry the microparticles obtained in step e).

The preparation of the aqueous pectin suspension is suitably carried outwith heating, e.g., up to a temperature of about 90° C. To the pectinsuspension, the active ingredient (the carotenoid and/or otherphysiologically active ingredient) is then added at a temperature ofabout 50-70° C., particularly at about 50-65° C. (step b).Emulsification (step c) is suitably carried out at the same temperaturerange while lower or higher temperatures, e.g. temperatures in the rangeof from 30-90° C. are also possible.

The ionotropic gel formation of low methoxylated pectin can be inducedby cations of two or more valencies, such as Ca++, Mg++ and Al+++,especially Ca++. Thus, every sufficiently water-soluble salt of suchcations, e.g., Ca-lactate, chloride dihydrate, citrate or triphosphatecan be used in step d). Suitably, the concentration of the calcium saltsolution is about 0.1 to about 0.6 molar. The so-obtained microparticlescan be separated and, if desired, be dried by conventional means, e.g.by centrifugation (step e) or freeze-drying (step f).

The process of the invention is illustrated further in FIG. 1 as well asin the Examples.

In still another aspect, the present invention relates to foodcontaining a composition comprising a pectin and a carotenoid or mixtureof carotenoids, and/or other active ingredient(s), as defined earlier.

It has surprisingly been found that the composition as set out above isvery well suitable to deliver the carotenoid (or other appropriatephysiologically active ingredient) where they are desired for thepurpose. Carotenoids (or other physiologically active ingredients) whenencapsulated in pectin, can pass the stomach and small intestine in amostly intact form (i.e. more than 50% of the particles remain intact)and may reach the large intestine (the colon) without substantial uptakeat earlier stages of the intestinal tract. Without wishing to be boundby theory, it is believed this is due to the properties of the pectin,which is hard to digest or to break down by the human body's ownenzymes. It is thought that once in the colon, however, microorganismsthat are present in the colon will produce enzymes which break down thepectic material. Such enzymes may be e.g. pectin lyases and pectatelyases and polygalacturonases. It is believed that pectin is quiteunique in this respect, and as an additional advantage said pectinparticles are relatively easy to prepare, and pectin is considered awell-accepted functional ingredient, especially in plant-derived foodpreparations.

The compositions according to the invention are preferably such that acarotenoid is encapsulated by or embedded in the pectin. Suchencapsulated or embedded carotenoids may be used as part of a food ordietetic composition, preferably in an aqueous composition. Examples ofsuch liquid or viscous food compositions are fruit or vegetable juicesand sauces/purees, (dietetic) fruit or vegetable drinks and (sports)drinks. Such food compositions may be prepared by adding an appropriateamount of a pectin composition to the food. Suitably, up to 1 g of apectin composition acording to the invention is added to 1 litre of abeverage to provide about 20 mg/l of provitamin A and to achieve anappropriately intense colour of the beverage.

Preferably the composition according to invention comprise at least 1%(by weight, based on the dry weight of the total composition)) of acarotenoid or other physiologically active ingredient(s). In principleall carotenoids may be used in the compositions according to theinvention. Preferred carotenoids are α-carotene, β-carotene, lycopene,astaxanthin, canthaxanthin, lutein, zeaxanthin, or mixtures thereof.Examples of other physiologically active ingredients for use in thepresent invention are polyunsaturated fatty acids such as arachidonicacid or docosahexaenoic acid; tocopherols such as α-tocopherol;phytosterols; and phytostrogens. In a preferred aspect of the invention,the active ingredient is a carotenoid, especially β-carotene includingits (natural) mixtures with other carotenes.

The compositions according to the invention may comprise furtheringredients such as (vegetable or essential) oils in which thecarotenoid (or other physiologically active ingredient) may be dispersedor partly or completely dissolved. In such compositions the carotenoidmay be dispersed in oil at a ratio (by weight) of carotenoid:oil between1:500 and 1:2.

Further additional ingredients may be compounds also exhibitingbeneficial effects in the colon and which may prevent the stomach andsmall intestine from irritation and which should pass the stomach andsmall intestine without breakdown or digestion, respectively, or may becomponents that help stabilise the composition, e.g. antioxidants, orcomponents that are found together with carotenoids. A preferredantioxidant is α-tocopherol, e.g. in an amount of 0.01-5% by weight.

Compared to gelatin-based compositions, the use of pectin asencapsulating material according to the invention provides a furtherbenefit when applied as an additive in fruit/vegetable juices orfruit/vegetable drinks with high fruit contents. Fruits contain a rangeof polyphenols, which in the presence of protein (e.g. gelatin) mayinteract to form a deposit of cloud, resulting in unattractive products.The use of pectin-based carotene compositions avoidsprotein-polyphenol-reactions and may therefore be suitable for producingattractive juices and drinks.

The invention is illustrated further by the Examples which follow.

EXAMPLE 1 Preparation of β-Carotene-Containing Microcapsules

For preparation of dry β-carotene-containing microcapsules a process wasfollowed as shown in FIG. 1.

2 kg of an aqueous suspension of 3% (by weight) of low methoxylatedpectin (“Pektin Classic AU-L 062/00” as obtainable from Herbstreith &Fox, D-75305 Neuenbürg, Germany) was prepared at 80° C. using anUltraturrax at 20.0000 rpm. To this suspension, 15 ml of a 30%dispersion of β-carotene in vegetable oil were added at a temperature of55° C. under stirring, and the mixture was emulsified in an in-lineTurrax at 15.000 rpm. The so-obtained emulsion was then sprayed into a0.1 m calcium chloride solution. The formed microgel particles wereseparated using a centrifuge. After washing, the particles werefreeze-dried to yield a red-coloured powder containing ca. 2% by weightof β-carotene. Particle size: 60% by weight had a size between 1 and 50micron.

Sustained release of the active ingredient was tested by incubation ofthe microparticles with artificial gastric juice and with pectolyticenzymes at 35° C., and quantified by HPLC as described by MARX et al.(2000): Food Chemistry 70, pp. 403-408.

EXAMPLE 2 β-Carotene-Fortified Orange Juice

Using the dried particles as prepared following example 1, a fortifiedorange juice may be prepared which contains 0.2-0.5 mg β-carotene/100 mlto intensify the natural orange colour of the juice.

Particle sizes are preferably below 5 micron.

EXAMPLE 3 β-Carotene-Fortified Fruit Drink

An apple juice drink (juice content 25%) with up to 1 mg of carotene/100ml drink may be prepared using the dried particles as prepared followingexample 1.

This may be achieved by mixing the dried particles according to theinvention (particle size preferably less than 5 micron) with water,sugar syrup, apple juice concentrate, lemon juice, ascorbic acid, andaromas. This mixture may be homogenised, pasteurised, degassed, filledinto bottles and cooled. When kept in the dark at room temperature, nosubstantial undesired deposit will be formed within 12 months.

In this case the particles are used to yield both a colouring and anutritional benefit.

After ingestion of this drink, the pectin wall of the particles will bebroken down by the colon microflora and the carotene content will bereleased.

1. Edible composition comprising at least 25% by weight (based on thedry weight of the total composition) of a pectin, wherein the pectin hasa degree of esterification (DE) below 50%, and at least 0.2% by weight(based on the dry weight of the total composition) of a carotenoidand/or another active ingredient.
 2. Composition according to claim 1,comprising at least 50% by weight (based on the dry weight of the totalcomposition) of pectin.
 3. Composition according to claim 1, wherein thepectin has a degree of esterification (DE) between 30 and 45% andcomprises between 60 and 75% of galacturonic acid units.
 4. Compositionaccording to claim 1, wherein the pectin is apple pectin or citruspectin or a mixture thereof.
 5. Composition according to claim 1 in theform of a dry powder.
 6. Composition according to claim 1, comprising atleast 1% by weight (based on the dry weight of the total composition) ofa carotenoid.
 7. Composition according to claim 1, wherein thecarotenoid is selected from the group consisting of lycopene,α-carotene, β-carotene, astaxanthin, canthaxanthin, zeaxanthin, lutein,and mixtures thereof, respectively.
 8. Composition according to claim 1,further comprising 0.01-5% by weight (based on the dry weight of thetotal composition) of an antioxidant.
 9. Composition according to claim8, wherein the antioxidant is α-tocopherol.
 10. Composition according toclaim 1, wherein the carotenoid is dispersed in oil at a ratio (byweight) of carotenoid:oil between 1:500 and 1:2.
 11. Compositionaccording to claim 1, wherein the carotenoid is completely or partlydissolved in oil at ratio (by weight) of carotenoid:oil between 1:1000and 1:5.
 12. Composition according to claim 1, wherein the carotenoid isencapsulated by the pectin.
 13. Food comprising a composition accordingto claim
 12. 14. Food according to claim 13, which is a fruit juice orvegetable juice, sauce/puree, (dietetic) fruit or vegetable drink or(sports) drink.
 15. Process for the preparation of a compositioncomprising a carotenoid and/or another active ingredient, which processincludes the following steps: a) prepare an aqueous suspensioncomprising a pectin, wherein the pectin used has a degree ofesterification (DE) below 50%, b) add a composition comprising at least0.5% by weight (based on the dry weight of the final composition) of acarotenoid or mixture of carotenoids, and/or other active ingredient(s)and, optionally, an oil to the suspension as prepared in step a), c)emulsify the mixture, d) spray the emulsion as prepared in step c) intoa bath of an aqueous solution of a salt of a cation of two or morevalencies, e) separate the formed microparticles from the bath and,optionally, wash the microparticles, and f) optionally dry themicroparticles obtained in step e).
 16. Process according to claim 15,wherein the pectin used in step a) is apple pectin or citrus pectin or amixture thereof.
 17. Process according to claim 15, wherein the salt ofthe cation of two or more valencies used in step d) is selected from thegroup consisting of calcium, magnesium and aluminium salts.
 18. Processaccording to claim 17, wherein the salt of the cation of two or morevalencies used in step d) is a calcium salt.
 19. Composition comprisinga pectin with a degree of esterification (DE) below 50% and a carotenoidand/or another ingredient obtainable by a process as claimed in claim15.